In recent years there has been an increasing interest in polymers derived from non-petroleum sources. These bio-derived polymers are more sustainable since they are derived from renewable sources and can be made from domestically produced monomers. Unfortunately most bio-derived polymers have been technical constrained in durable applications by having low glass transition temperatures (Tgs) (and hence, low heat distortion temperatures for amorphous polymers), low impact strength, and limited hydrolytic stability.
A key example of a commercially available bio-derived polymer is poly lactic acid, or PLA, that is derived from the fermentation of sugar from corn, but soon to be from tapioca, sugar cane, and eventually cellulose. Sugar is fermented to lactic acid which is converted into lactide (dimer of lactic acid) chemically and further chemically polymerized to polymer. PLA is clear and 100% bio-derived but unfortunately has a low Tg of about 56° C. and is brittle. Attempts have been made to develop higher glass transition polymers via copolymerization with monomers such as furan/isosorbide that yield furan/isosorbide that yield higher Tg polymers. Unfortunately these monomers are currently either in short supply or very expensive.